Sensitivity of the integrating pulse magnetometer with a first-order gradiometer

Abstract

Inductive magnetometers used for measurements in pulsed magnetic fields should have proper frequency characteristics. In the present work we describe the construction of an inductive magnetometer for measurements of the magnetic moment in pulsed magnetic fields, together with the calculation procedures for determination of its sensitivity. We present a method for determination of the effective coefficient of the coupling between the coils set (gradiometer) and cylindrical samples, as well as a method for calculation of the thermal noise in the measuring system. The determination of the effective coupling coefficient permits a straightforward connection of the value of the measured signal with the magnetic moment of the sample and calibration of the gradiometer in absolute units. In the work we also present, as examples, some experimental hysteresis loops of pulse magnetization measurements for some ferromagnetic samples and a single crystal of high temperature superconductor. The results were obtained using our homemade pulse magnet and magnetometer with a gradiometer designed and constructed on basis of presented here calculations.